Circuit Design

 UM 3561 is an excellent Siren generator IC widely used in Toy applications and Surveillance systems to generate different tones. It a ROM (Read Only Memory) IC which can be operated in 2 pen cells and it functions normally down to 2.4 volts. Using only a few components, it is very easy to construct a…

The amplifiers are devices which produces an output signal which is several times higher in amplitude than the input signals. The ratio of the amplitude of the output signal from an amplifier circuit to the amplitude of the input signal is called Gain. The amplifier circuits are normally designed for a fixed amount of gain. There are amplifiers with very low gain, like the amplifiers at the loudspeaker side of an audio device and also there are amplifiers with very high gain, like the amplifiers in the radio receivers or amplifiers at the microphone side of an audio device. The Automatic Gain Control (AGC) amplifiers are another category of amplifiers which can vary its gain according to the input signal level. They provide enough amplification for the weak signals and prevent strong signals from getting over amplified.  

This article discusses how to design a simplest active bass separator circuit with design details. This is basically a low pass circuit which is used to separate out low frequency sounds from audio signals at audio play back devices. A simple loudspeaker is not capable of reproducing all the frequencies of the audible range. Different kinds of loudspeaker are available which can reproduce the sound at certain range of frequencies. The bass separator circuit alone is realized with the help of commonly available op-amp ICs. For demonstrating the working a bass beat is played in a mobile phone which is captured, amplified and mixed with a high frequency musical signal and is then again separated out using the bass separator circuit and reproduced in a loudspeaker. Read more to find out how the circuit is assembled and how it is tested and used.  

This article discusses about a simple circuit that can reproduce the sound signals captured through a microphone on a loudspeaker. The microphone is a device which is used to capture sound signals and forms an essential part of most of the electronic gadgets. The microphone converts the sound signals in the environment to their corresponding electrical signals.

How to deal with any unknown stepper motor? This section deals with a special procedure that can be useful to find out the type of stepper motor, its terminals, its coil sequence, its step resolution and everything about stepper motor. if anyone have a stepper motor that doesn’t have any specifications then after going through this section…

This is programmable FM remote control can be used for some specific applications. Phase Lock Loop (PLL) IC-567 is used in transmitter and receiver part as oscillator and filter respectively. It can operate/control any device / application from the distance of around 50 meter (this range can be increased up to 1-2 Km if good…

Road safety is a critical concern, with driver fatigue and distractions among the leading causes of accidents. In this project, we’ll devise a smart system using Arduino UNO and a blink-eye sensor to monitor driver alertness. If the driver shows signs of drowsiness, the system takes proactive measures to prevent a potential accident. This includes…

These smart clocks, powered by the ESP8266 D1 Mini, offer more than just timekeeping. In addition to displaying the current time, they measure temperature and humidity, making them versatile tools for monitoring environmental conditions. Equipped with a DHT22 sensor, these clocks provide accurate air temperature and humidity readings, displayed alongside the time on a 1.8-inch…

The voltage requirements for different circuits vary much like microcontroller-based circuits require 5 V, motor controller or relay driver circuit requires 12 V, and other digital circuits require 3.3 V.  If a circuit fails to receive its rated voltage and current, it will not work properly. So, it often makes sense to use a variable…

Smart technology refers to devices and systems that use advanced computing, connectivity, and data analytics to enhance functionality and efficiency. Devices such as smartphones, watches, and appliances connect to the Internet and one another via the Internet of Things (IoT), allowing for real-time data exchange and remote control. One innovative application of this technology is…

Depending on the country, as many as 25 to 35% of motor vehicle accidents happen because of drunk driving every year. When drivers consume alcohol, they not only put themselves at risk but others on the road. Fortunately, such accidents are preventable with a combination of education, personal responsibility, and community efforts. There are also…

In this project, we’ll design a wireless joystick dc motor controller using ATtiny85 and Arduino. It will offer a long range, operating up to 1 km. (You can learn how to control the joystick’s motor speed and direction using Arduino in this article.) Wireless joystick controls for dc motors are used in many industrial, domestic,…

Look inside this one-chip clock built from surplus parts. With the case open, replacing parts waiting to fail seemed like a good idea. In my second year at WPI, I found myself in “B term” where I had a scheduling problem. Being as WPI operates on a four-term academic year, I couldn’t find a one-term…

It’s been said that one of the best home security systems is owning a dog. In this do-it-yourself (DIY) circuit, we’ll design a unique system that lets you take advantage of a guard dog for security without ever needing to walk or feed it. This DIY system “barks” like a dog whenever motion is detected…

Inductors are simple components in electronic devices that perform tasks like cleaning up electrical signals, helping with timing, and managing power. They store energy in magnetic fields when electricity flows through them and releases them back into the circuit. Inductors resist sudden changes in the flow of electricity, pushing back “spikes” by creating an electrical…

In this project, we will learn to create an automatic water pump system circuit that switches ON and OFF based on the water level in the tank. Basic idea The given project demonstrates a simple circuit built using digital logic gates, IC NE555, transistors, and a few additional components that sense the water level in…

 You can use this Simple Alarm to protect the door or Window. It gives a loud beep and switch on the room light when an intruder/burglar attempts to breaks the door lock. The alarm functions only after 5 minutes to confuse the intruder. Working of this burglar alarm circuit is simple. IC1 is used to…

 This circuit can protect your Electronic devices like TV from inrush current. Very high spikes can develop at power on due to sparking in the switch and more serious effects occur when power resumes after a power failure due to high magnetic field in the distribution transformer. When we keep the TV in standby mode through…

This circuit can sense the overload condition and breaks the power if the load increases above the set point. It is an ideal circuit to protect Uninterrupted Power Supply devices like Inverter.Let us see its working …The Optocoupler MCT2E and the Resistor R3 (1 Ohm 10 Watts) will do the trick. The Optocoupler has an LED and a Phototransistor inside with connecting leads. The LED of MCT2E is connected parallel to the resistor R3 with a current limiter R2 for the LED. The phototransistor of Optocoupler is connected to the transformer derived 9 volt DC through the current limiter R1. The load is connected through the Common and NC contacts of the relay. So it will work normally at power on.

 This light triggered circuit can be used to turn on / off a load such as lamp through the IR rays from a remote or light from a torch. This is an ideal circuit to switch on / off the room light using TV remote while watching the TV .The circuit uses a Phototransistor and…